Photographic product and a process of additive color photography



June 23, 1964 E. H. LAND PHOTOGRAPHIC PRODUCT AND A PROCESS OF ADDITIVE COLOR PHOTOGRAPHY 2 Sheets-Sheet 1 Filed Dec. 9, 1959 INgVTOR.

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ATTORNEYS E. H. LAND PHOTOGRAPHIC PRODUCT AND A PROCESS June 23, 1964 OF ADDITIVE COLOR PHOTOGRAPHY 2 Sheets-Sheet 2 Filed D60. 9, 1959 ATTORNEYS E Z /ENTOR. aw wzd,

United States Patent 3,138,459 PHOTUGRAPHZC PRODUCT AND A PROCESS 0F ADDITKVE COLOR PHOTOGRAPHY Edwin H. Land, Cambridge, Mass, assignor to Polaroid Corporation, Cambridge, Mass, a corporation of Delaware Filed Dec. 9, 1959, Ser. No. 858,551 43 Claims. (Cl. 96-3) This invention relates to photography and, more particularly, to processes and products for use in the production and exhibition of color images.

This application is a continuation-in-part of my copending application Serial No. 596,033, filed July 5, 1956.

Conventional additive color processes are of two general types. In one type, two or three continuous tone color separation records are produced, usually representing the primary colors, and are exhibited simultaneously by light directed through filters corresponding to the colors represented by the records. In the other type, two or three segmented records are produced by light transmitted through a filter screen or filters associated with a beam-splitting device and are viewed by light transmitted through the same or a similar filter screen or beamsplitting device. The final transparencies produced by screen processes of this latter type are subject to considerable color desaturation due to spreading or ditfusion of the images behind adjoining filter elements particularly during exposure caused by irradiation in the emulsion and diflraction by the screen elements. Thus, in these prior art processes color desaturation could be reduced to acceptable proportions only by reducing this ditfusion as by using emulsions of high resolving power which Were in general too slow for ordinary photographic purposes.

The present invention has, as one of its objects, the provision of a novel additive color process which is a combination of the above-mentioned processes for producing a screen type additive color transparency and which is characterized by its freedom from the color desaturation normally associated with additive screen processes. The process of the invention eliminates the dependency of good color saturation upon the high resolving power of the emulsion, and, as a result, it becomes possible to employ fast negative materials of normal resolving power in the process of the present invention without adversely afiecting the color saturation of the final image. More broadly, it separates the problems involved in resolving power from the problems involved in color saturation.

Other objects of the present invention are: to provide an improved process of additive color photography wherein at least two nonsegmented color separation records are formed in two photosensitive layers and two segmented images corresponding to each of the color separation records are formed therefrom on a single support with the segments of said images in side-by-side relation to produce a positive additive print; to provide a process as described wherein each of said segmented images is formed by distributing a fluid between one of said photosensitive layers and one side of said support sheet; to provide a color process as described wherein said positive images are formed by transfer of an image-forming substance from said photosensitive layers and wherein said image segments are formed in substantially coplanar non-overlapping relationship; to provide an additive color process as described wherein additive color filter elements are provided in association with positive image segments; and to provide an additive color process as described above of forming color reproductions which may be carried out simply and rapidly as, for example, in apparatus such as a camera in which exposure of the photosensitive material is eifected, the composite additive print being attainable shortly after exposure.

3,138,459 Patented June 23, 1964 Still other objects of the invention are: to provide a novel product which embodies within itself substantially all of the materials necessary for carrying out the above process; to provide a product of the above type comprising a sheetlike element capable of supporting a screen arrangement of filter elements including at least one additive color and two segmented positive images corresponding to and formed from the two nonsegmented color separation records; to provide, in a product of the above type, a transparent sheetlike element comprising a multiplicity of minute recesses in at least one of its surfaces, the color process utilizing said transparent element which involves providing each of the recesses with at least a colored filter material and a segment of a positive image corresponding to a segment of a color separation record; to provide a product of the above type including a fluid composition capable of effecting the transfer of imageforming substances from said photosensitive layers to said support element; and to provide a product as described wherein said colored filter material is provided in said fluid composition for distribution in said recesses.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps and the relation and order of one or more of such steps with respect to each of the others, and the product possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a perspective view, partially in section, showing a photographic product embodying the invention;

FIG. 2 is a diagrammatic sectional view illustrating the process of the invention together with a typical camera employed in said process;

FIG. 3 is an enlarged and exaggerated sectional view through the product of FIG. 1 and illustrating the process of the invention;

FIG. 4 is an enlarged and exaggerated sectional view of an additive color transparency produced by the process of the invention; and

FIGS. 5 and 6 are views, similar to FIG. 4, showing other forms of transparencies produced by the process of the invention.

Generally the present invention envisions a novel method of producing an additive color print, preferably a transparency, beginning with the formation of two or more nonsegmented or continuous tone latent color separation records. From these nonsegmented color separation records are produced segmented, discontinuous positive images, the segments of at least one of the images being registered with a multiplicity of appropriately colored additive filter elements arranged in a screen pattern and carried on a preferably transparent support sheet. The positive image segments are produced preferably in substantially the same plane in side-by-side relation without overlapping and are formed by transfer of an imageforming substance, such as a dye or dye intermediate, or a soluble silver complex formed from silver halide from the photosensitive elements comprising the latent color separation records. Transfer of the image-forming substance from the photosensitive elements is effected in unexposed areas of the photosensitive elements registered with appropriately colored filter elements so that those areas of the finished transparency which have received the image-forming substance are rendered substantially opaque to transmitted light, as is the case with one form of conventional screen types of additive color transparency.

In accordance with the present invention, at least two photosensitive sheets, each comprising a photosensitive material, preferably a silver halide emulsion layer, are exposed to produce in said emulsion layers nonsegmented latent images of subject matter to be reproduced in color, each image representing a record of the intensity of a particular color of light from the subject. In a preferred form of the invention, each of these emulsion layers, containing a record representing a dififerent color, for example one of the primary colors, is superposed with one surface of a sheetlike transparent support with the two records located in registration. A positive reversed image of each latent image in a photosensitive sheet is obtained on the transparent support from the material of the silver halide emulsion layer. Each reversed image is formed as a multiplicity of spaced-apart minute segments or increments, each segment being associated with a filter element of a multicolor filter screen corresponding in color to the color represented by the image segment. All of the filter elements of each color are provided on one side or the other of the transparent support with filter elements of different colors, being so ararnged in an alternating repetitive pattern that no two elements overlap or obscure one another. After formation of the reversed image segments in association with filter elements of a color screen, the photosensitive sheets are separated from the transparent support and the latter, containing the color screen and reversed image segments, provides a positive polychrome transparency of the subject matter to which the two photosensitive sheets were exposed.

The process of the invention is particularly adapted to the production of a continuous tone positive color transparency comprising a two-color additive color screen, preferably of the primaries, such as red and green. Accordingly, red and green color separation records are first produced as latent images in separate silver halide emulsion layers by any of the methods now well known in the art. For example, the emulsion layers may be exposed in superposition, with each of the layers being sensitive to wavelengths of light in the red or green range, or the two emulsion layers may be exposed simultaneously, while spaced apart, through red and green filters with the aid of a beam-splitting device comprising a component of a camera or other photographic apparatus adapted to the exposure and processing of photosensitive materials. The reversed or positive images are formed by silver halide transfer reversal on a suitable transparent support or receiving sheet and, in the present example wherein two-color separation records are involved, may be formed on spaced-apart segments on opposite sides of the support sheet.

Reference is now made to FIGS. 1 and 3 of the drawings wherein there is illustrated one form of a novel photographic film assemblage, indicated at 10, for carrying out the processes comprehended by the invention, the film assemblage comprising substantially all of the materials required to obtain the desired positive color transparency. In the form shown assemblage 10 comprises a pair of sheetlike photosensitive elements 12 and 1.4 and a sheetlike transparent support 16. Photosensitive elements 12 and 14 comprise, respectively, support layers 18 and 20 and photosensitive layers 22 and 24, the photosensitive layers covering at least areas of support layers 18 and 20 which are adapted to be exposed and which are generally coextensive with one another. Photosensitive elements 12 and 14 are secured together in facing relation with support layers 18 and 20 located outermost and with photosensitive layers 22 and 24 disposed toward one another. Support layers 18 and 20 may be of any suitable sheet material either opaque or transparent, depending on the intended method of exposure. In the form shown, photosensitive layers 22 and 24 are intended to be exposed while in spaced-apart positions so that support layers 18 and 20 may be formed of any opaque or transparent material commonly used as a film base, such as paper, sheet plastic or the like, and for purposes of the invention are preferably formed of a sheet material having at least some flexibility so that the photosensitive elements may be folded or bent.

Each of photosensitive elements 12 and 14 includes a first portion designated, respectively, 12a and 14:: comprising the area adapted to be exposed, and a second portion designated, respectively 12b and 14b. The photosensitive elements are secured together in facing relation at opposite edges of portions 12!; and 14b adjacent one edge of portions 12a and 146 by any conventional fastening means such as staples 26. By virtue of this arrangement portions 12a and 14a of the elements may be spaced apart for exposure, while portions 12b and 14b are fixedly retained with respect to one another so that when exposed portions 12a and 14a are again superposed with one another, the latent images formed therein will be registered with one another. The elements are preferably flexible so that each element itself functions as a hinge connecting the two portions thereof. If it is so desired, the two portions of each element may be separate and distinct rather than integral and suitable hinge means may be provided for securing the two portions of each element together.

Transparent support 16 is located between elements 12 and 14 and includes a first section 16a at least coextensive with the exposure areas of portions 12a and 14a and superposable therewith, and a second section 16b located between portions 12b and 14b. The Width of support 16 is preferably such that it is slidable with respect to elements 12 and 14 between staples 26 so that first section 16a of support 16 may be moved, if desired, from its position between portions 121: and 14:: during exposure of elements 12 and 14.

At least first section 16a of support 16 comprises a transparent sheet of substantially uniform thickness, ranging from 0.003 to 0.015 inch, and may be of any of a variety of optically clear materials, such as glass and glasslike organic polymers including most of the plastic materials conventionally used for transparent film base such as cellulose esters, styrenes, acrylates and vinyl chloride copolymers. Support 16 is provided in each surface with a multiplicity of minute recesses in the form of spaced parallel channels or grooves 23 with the spacing or elevated portions between grooves in one surface at least equal to the width of the grooves in the opposite surface and with the grooves in each surface located opposite nongrooved or elevated portions of the opposite surface, so that depthwise of the support no two grooves overlap. The recesses in the surfaces of support 16 are preferably in the form of grooves for convenience of manufacture, it being understood that minute recesses of any desired shape and arrangement may be satisfactory and are within the scope of the invention so long as recesses in opposite surfaces of support 16 do not overlap.

In the form shown in FIG. 3 the depth of grooves 28 is less than half the thickness of support 16 and the width of the grooves is substantially equal to the elevated portions between the grooves so that the side walls of opposed grooves are in alignment. For example, the recesses could be rectangular or square and could be arranged in each surface of support 16 in a checkerboard pattern. The recesses or grooves are preferably provided with substantially plane, perpendicular sides and plane bottom surfaces. In an alternative form of support 16 shown in FIG. 5, the spacing between grooves 28 in each surface is greater than the width of the grooves in the opposite surface so that the depth of the grooves may equal or exceed half the thickness of support 16. While the grooves in the opposite surfaces of the support have been illustrated as being substantially equal in width, the grooves in opposite surfaces may be of different widths, for example in order to achieve variations in the color balance of the finished positive color transparency. Th Width of the grooves is submicroscopic and is such that the number of grooves per inch in each surface may range as high as 250, depending on the extent to which an additive color transparency comprising grooved support 16 is to be magnified during exhibition.

The reversed continuous tone image segments corresponding to segments of the nonsegmented latent images produced in photosensitive layers 22 and 24 by differential exposure thereof are formed in grooves 28 either directly on the bottom surfaces of the grooves or on an intermediate layer located in each groove on the bottom surface thereof. The positive or reversed image segments are formed by a silver transfer-reversal process effected by a fluid composition distributed in each groove in contact with a segment of an exposed photosensitive layer. For this purpose photosensitive layers 22 and 24 each comprise a silver halide emulsion and the fluid composition responsible for the production of a positive transfer image of the latent image in the silver halide preferably includes a silver halide developer, a siliver halide solvent, a material providing a silver precipitating environment, and a thickening or film-forming agent. This fluid composition, when provided in a relatively thin layer on a differentially exposed silver halide layer, effects the reduction of exposed silver halide to silver and the formation with unexposed silver halide of a soluble complex which is reduced to silver in the fluid layer to form a positive image. Examples of photographic materials useful in processes of the foregoing type are described in detail in my Patent No. 2,662,822, issued December 15, 1953.

The fluid processing composition is preferably supplied in a pair of elongated rupturable containers 30 of substantially identical construction and associated with the inner surfaces of portions 12b and 14b of elements 12 and 14 or with the opposite surfaces of section 16b of support 16. Each container carries a quantity of fluid composition, indicated at 32, at least sufficient to completely fill the grooves in one surface of support 16 and is located between one surface of the support and one of elements 12 and 14. In the form shown each container 30 comprises a single rectangular blank of an airand water-vapor-imperivous sheet material folded longitudinally upon itself with its edges sealed together at the ends and along the longitudinal side to form an elongated fluid-carrying cavity. The longitudinal edge seal is weaker than the end seals, providing a discharge mouth extending substantially the full length of the liquid-carrying cavity and adapted to become unsealed and efiect the unidirectional release of the fluid when the walls of the container are subjected to compressive pressure. Containers 30 are located between portions 12b and 14b of elements 12 and 14 on opposite sides of support 16 with their discharge mouths located adjacent one edge of portions 12a and 14a in position to eject their contents between portions 12a and 14 and support 16 when subjected to compressive pressure.

Photographic elements 12 and 14 may be differentially exposed in a camera, for example as illustrated diagrammatically in FIG. 2, to produce a pair of latent color separation images. Elements 12 and 14 are positioned substantially at right angles to one another within a camera, generally indicated at 34, and exposed to light transmitted by a lens 36. A beam splitter, for example in the form of a half-silvered mirror 38, located in the path of light from lens 36 at a 45 angle with respect to the optical axis of the lens and the photosensitive elements, is provided for producing two separation images. Each photosensitive element is exposable by or is exposed to light of a different wavelength range preferably corresponding to one of the primary colors. The photosensitive layers may be panchromatic and exposure may be effected through filters; or the photosensitive layers may be specially sensitized over selected portions of the spectrum, or a light filter material may be incorporated into or provided on panchromatic emulsions. Following exposure, portions 12a and 14a of elements 12 and 14 are superposed with opposite sides of support 16 to form a sandwich and the entire assemblage is moved between a pair of pressure-applying members, as shown in FIG. 3, for spreading the fluid contents of containers 30 in grooves 28 between support 16 and elements 12 and 14. Movement is preferably in a direction normal to the direction of the grooves in order to better assure a uniform distribution of the fluid throughout the full length of the grooves. In the form shown these pressure-applying members comprise a pair of rolls 40 and 42 resiliently urged toward one another with sufficient pressure to have a doctoring action, insuring that fluid 32 is retained only in grooves 28 and is forced from between the nongrooved or elevated portions of support 16 and the segment of the photosensitive layer (22 or 24) superposed therewith. Thus, the reversed positive images of latent images in photosensitive layers 22 and 24 are formed only as spaced-apart segments in the fluid deposited in grooves 28.

An additive color screen is formed by providing a filter element in each groove 28, all the filter elements in the grooves in one surface of support 16 being the same color and the grooves in the opposite surface having elements all of a single different color. The filter elements may be provided in the grooves prior to spreading of processing fluid 32 by a doctoring process or a colored filter material may be incorporated in the processing fluid itself supplied in each of containers 30. In the form shown in FIGS. 3 and 4, the filter elements, indicated at 44 and 46, are provided in grooves 28 prior to deposit of the processing fluid therein and comprise elements of two colors, for example the primaries red and green. Filter elements 44 and 46 may be formed, for example, by depositing a fluid such as a plastic material containing suitable colored filter media such as dyes in the grooves by doctoring. The solid content of the fluid is controlled so that its thickness is reduced as it dries to a thin residual layer on the bottom surface of each groove. The thickness of the filter elements or layers is preferably a fraction of the depth of the grooves so that the processing fluid may be deposited therein on top of the filter elements. When the film assemblage is processed to produce an additive color transparency, the photosensitive element containing, for example, the red latent record is superposed with support 16 so as to cover the grooves containing red filter elements, and the other photosensitive element containing, for example, a green latent record is superposed wtih the support so as to cover the grooves containing green filter elements.

The filter material may be provided in the form of filter elements in the grooves in only one side of the support in order to produce a transparency which may be exhibited to give full color reproduction. For an example of such a color process wherein there is required only one set of color filter elements and only a difference in the transmission by the two images, reference may be had to Color Vision and the Natural Image, by Edwin H. Land in Proceedings of the National Academy of Sciences, Part 1, vol. 45, No. 1, pp. -129; January, 1959; Part II, vol. 45, No. 4, pp. 636-645; April 1959.

Fluid composition 32, when deposited in the grooves in contact with spaced-apart segments of photosensitive elements 12 and 14, effects the production of a positive or reversed image in the fluid in each groove, the image corresponding to the negative image in the segment of the photosensitive element which it contacts. This arrangement makes it unnecessary to provide for registration between a screen and a positive record and requires only that the two latent (or negative) records be registered with one another. This registration is easily achieved, since elements 12 and 14 are fixedly secured with respect to one another, and is not altered or disturbed due to the thickness of containers 30 located between the elements, since the containers are located on one side of the means (staples 26) retaining the elements together and the portions 12a and 14a thereof adapted to be exposed are on the opopsite side of the retaining means. Following spreading of the fluid composition in the grooves between support 16 and elements 12 and 14, a predetermined processing period is permitted to elapse, during which positive reverse dimages are formed in the fluid in the grooves.

At the end of this processing period elements 12 and 14 are stripped from support 16 and the support, containing the filter elements and the positive segmented images, comprises an additive transparency depicting, in substantially full color, the subject matter to which elements 12 and 14 were originally exposed. Section 16a of support 16, comprising the transparency, may be separated from section 16b to which are attached elements 12 and 14 and including collapsed containers 30 and this may be facilitated, for example, by providing a transverse line of perforations in support 16 at the juncture of sections 16a and 16b. The fluid deposits in grooves 28 may be subjected to a further treatment by a fluid composition, for example, as described in copending application Serial No. 555,433, filed December 27, 1955, in order to eifect the preservation of the positive silver images and the hardening of the fluid deposits. As each of the fluid deposits hardens into a solid image-containing film, designated 48, it may shrink in thickness so that the levels of the deposits are below the surfaces of support 16 and are extremely thin, thereby reducing the depthwise spacing between the planes of the red and blue records.

Other mechanisms are contemplated by the invention for producing two segmented transfer images on opposite sides of the support from two continuous tone colorseparation records. One such approach is to coat minute areas on each side of the support arranged in a screen pattern with a hydrophobic material such as a grease which will prevent both wetting of the support in the areas coated and formation of a transfer image in said areas. The layers of processing fluid distributed between the photosensitive layers and the sides of the support would be continuous, but wetting of, and hence transfer to, the image-receiving support is limited to only those areas left free of the hydrophobic material. The uncoated areas of the support may be provided with a filter material which may be absorbed into the support during the manufacturing process or the filter material may be provided in the aqueous processing fluid.

Another mechanism for forming segmented transfer images is to provide a transferable image-forming substance in the photosensitive layers, which substance requires a specially constituted image-receiving layer in order to form a visible image thereon. Such image-formmg substances include dyes and dye intermediates while the image-receiving layers comprise materials substantive to the dye or materials reactable with the dye intermediate to form a dye. In this embodiment only certain areas of each side of a support are provided with the appropriate material for receiving or combining with the imageforming substance to form a dye image. For example, minute areas of the sides of the support may be provided with substantially nondiifusible color formers or couplers which react with the oxidation product of a color developer to produce a dye, the color developer being provided in the photosensitive layers or in the processing fluid. In this embodiment, the oxidation prodoxidized, and the resulting oxidation products are coupled with color couplers located in the image-receiving layers. Examples of materials suitable for this purpose are found in the following patents issued to Edwin H. Land: 2,559,643, issued July 10, 1951; 2,661,293, issued December 1, 1953; 2,698,244, issued December 28, 1954; and 2,698,798, issued January 4, 1955.

The image-forming substance may comprise, instead of the oxidation product of a color developer, a dye or dye intermediate which must be oxidized, for example, following transfer to form a visible transfer image of the proper color in a layer containing the oxidizing agent which is provided only in discrete areas of said layer on the receiving sheet. Suitable materials for this purpose include leuco dyes, i.e., dyes utilized in their leuco or reduced form and which are capable of developing exposed silver halide as a result of being in the leuco state, but which must be oxidized after transfer to the image-receiving layer in order to provide the desired dye. For an example of such materials, reference may be had to U.S. Patent No. 2,909,430, issued October 20, 1959 to Howard G. Rogers.

Another material for this purpose is a complete dye which is capable of coupling with the oxidation product of a color developer, e.g., ethyl para-phenylenediamine to form an immobile dye. For examples of such a material reference may be had to U.S. Patent No. 2,774,668, issued December 18, 1956, to Howard G. Rogers.

Another form of additive two-color transparency produced by the process of the invention is illustrated in FIG. 5 and comprises a transparent support 50 having parallel grooves 52 in opposite sides and image segments 54 within the grooves on the bottom surfaces thereof. Colored filter matter is provided in the fluid composition forming the image segments 54 so that they also comprise the filter elements of the transparency. Grooves 52 in support 50 are spaced apart by a distance greater than the width of the grooves so that the depth of the grooves may equal or exceed half the thickness of the support. One advantage of this particular construction resides in the fact that the two segmented positive images may be located in the same planes or in planes that are relatively close to one another.

An additive three-color transparency produced by a modification of the process of the invention is illustrated in FIG. 6 of the drawings. This transparency comprises a transparent support 56 having parallel grooves 58 in its opposite sides, the nongrooved surface or elevated portions of the support, indicated at 60, being appreciably wider than the grooves themselves. A pair of positive segmented color separation records are provided as layers 62 deposited on the bottom surfaces of the grooves. These two records, each for a different color such as the primaries red and green, are produced in the manner described and layers 62 include appropriately colored filter matter so as to act as filter elements. A third positive color separation image is provided in the form of increments, indicated at 64, on one surface of support 56 on the nongrooved or elevated portions 60 of the surface at locations between opposed grooves 58.

Positive image increments 64, representing, for example, the third primary, blue, are formed by a silver halide diffusion transfer-reversal process of the type described in my Patent No. 2,543,181, issued February 27, 1951, following formation of image layers 62 by the method already described. In the formation of image increments 64, a fluid processing composition is spread in a thin layer between nongrooved or elevated surface portions 60 and the silver halide emulsion layer containing a nonsegmented latent color separation image. This fluid composition effects the reduction of unexposed silver halide in an image-receptive environment provided in a surface stratum of support 56. This image-receptive environment or surface stratum is provided only in the nongrooved or elevated portions 60 of one surface of support 56 between opposed grooves 62 and, since the positive silver transfer image is formed only in this silverreceptive environment, the third image is formed in spacedapart segments located lengthwise of support 56 between segments of the other two images. Following formation of this third segmented image, the silver halide layer is stripped from support 56 and the. layer of fluid composition spread therebetween is so constituted as to adhere to the silver halide layer so that it too is removed from support 56. The filter elements for this third or blue image are provided, for example, by dyeing the surface of support 56 in the regions of the separate silver precipitating strata, or suitable color filter material may be provided in the silver-receptive strata themselves.

As previously mentioned, this invention contemplates production of the positive image by transfer of imageforming substances, from the class consisting of dyes and intermediates for dyes, as well as silver, from the photosensitive elements to the filter-carrying support. For example, an image-forming subtance capable of effecting the formation of a red, blue or cyan dye could be trans ferred from the unexposed areas of the photosensitive element containing the latent green separation record to the support opposite or in registration with red filter elements, rendering those areas in which a blue, cyan or red dye is located in registration with a green filter element substantially opaque to transmitted light, as would be the case with silver. It is apparent that the high degree of opacity needed for best results can best be obtained with high contrast emulsions. Additionally, the invention is applicable to the production, from two or more negative color separation records on a single side or surface of a transparent support, of two or more segmented positive color separation images in registration with appropriately colored filter elements. This may be achieved by a proper selection and arrangement of materials comprising the photosensitive elements, support and fluids distributed therebetween, such materials, their arrangement and methods of employing them being familiar to persons skilled in the art.

Since certain changes may be made in the above product and process without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. The method of additive color photography which comprises exposing two photosensitive layers, each comprising a photosensitive heavy metal salt capable of having a developable latent image formed therein by exposure to actinic light, to produce in said photosensitive layers latent nonsegmented color-separation records; superposing said photosensitive layers with opposite sides of a support sheet with said records in substantial registration; distributing a fluid processing composition between each of said photosensitive layers and one side of said support sheet; by said fluid, developing said latent color-separation records and producing in said photosensitive layers as a result of said development imagewise distributions of transferable image-forming substances; transferring'said image-forming substances by diffusion substantially only from minute spaced-apart areas of said photosensitive layers arranged in a photographic screen pattern to said support sheet and thereby forming on said support sheet two segmented positive transfer images corresponding to said color-separation records and arranged with the segments comprising each of said positive transfer images spaced apart from one another and located in alignment with the spaces between the segments comprising the other of said transfer images, each of said image segments comprising a light-transmitting and absorbing element; providing the elements comprising one of said transfer images with a material for transmitting light in a predetermined portion of the visible wave length range;

and providing the elements comprising the other of said transfer images with a material for absorbing light in said predetermined portion of the visible wave length range, the last-mentioned material being so associated with the segments of said other transfer image as to determine the wave length range of the light transmitted by the lastmentioned elements.

2. The method of claim 1 wherein said last-mentioned material is provided in a form of filter elements mounted on said support sheet in alignment with said image segments of said other transfer image.

3. The method of claim 2 wherein said last-mentioned material is initially provided in said fluid composition which is distributed between said support sheet and one of said photosensitive layers, and said last-mentioned material is associated with said support sheet by spreading of the said last-mentioned fluid in contact with said support sheet.

4. The method of claim 1 wherein said segments comprising said one transfer image are formed in coplanar nonoverlapping relation in portions of a first discontinuous receiving layer and said segments comprising said second transfer image are formed in portions of a second discontinuous receiving layer located in substantially coplanar nonoverlapping relation with said portions of said first receiving layer.

5. The method of claim 1 wherein said photosensitive heavy metal salt is silver halide, said image-forming substances comprise a soluble silver complex formed from unexposed silver halide, and said silver complex is reduced to silver to form said positive image segments on said support sheet.

6. The method of claim -1 wherein a first fluid composition is distributed between one of said photosensitive layers and said support sheet for producing said elements comprising said one transfer image and a second fluid composition is distributed between the other of said photosensitive layers and said support sheet for producing said elements comprising said other transfer image, said fluid compositions containing the materials for determining the wave length range of the light transmitted by said lighttransmitting and absorbing elements.

7. The method of claim 1 wherein said fluid processing composition includes water and said fluid is so distributed as to substantially wet only those portions of said support sheet on which said transfer image segments are formed.

8. The method of claim 7 wherein said fluid processing composition is squeezed from between each of said photosensitive layers and the remaining portions of said support sheet between the first-mentioned portions thereof on which said image segments are formed.

9. The method of claim 7 wherein the remaining portions of said support sheet between the first-mentioned portions thereof on which said image segments are formed are provided with a surface coating of a hydrophobic material.

10. The method of claim 1 wherein said image-forming substances produced in said photosensitive layers comprise materials selected from the class consisting of dyes and intermediates for said dyes and only those portions of said support sheet in which said transfer image segments are formed are provided with one of a material receptive to said dyes and a material reactable with said dye intermediates for forming said dyes.

11. The method of claim 1 wherein image-forming substances are transferred by diifusion from minute spacedapart areas of a third exposed photosensitive layer comprising a heavy metal salt capable of having a developable latent image formed therein by exposure to actinic light, arranged in a screen pattern to one side of said support sheet to form thereon a third segment positive transfer image with the segments comprising said third image located between the segments of the first-mentioned images; and the segments comprising said third transfer image are provided with a material for absorbing light in a wave length range different from said predetermined wave length range, the last-mentioned material being so associated with said segments of said third transfer image as to control the wave length range of light transmitted by light-transmitting and absorbing elements comprising said segments of said third image.

12. The method of claim 1 including the steps of exposing a third photosensitive layer comprising a photosensitive heavy metal salt, capable of having a developable latent image formed therein by exposure to actinic light, to produce in said third layer a third nonsegmented color-separation record; superposing said third photosensitive layer with one side of said support sheet with said third record in substantial registration with the first-mentioned records; distributing a fluid processing composition between said third layer and the last-mentioned side of said support sheet; by said fluid, developing said third latent color-separation record and producing in said third layer as a result of said development an imagewise distribution of third transferable image-forming substances; transferring said third image-forming substances by diflusion from substantially only minute spacedapart areas of said third photosensitive layer arranged in a screen pattern to said last-mentioned side of said support sheet and forming thereon a third segmented positive transfer image corresponding to said third color-separation record with the segments of said third image spaced apart from one another and located between the segments comprising the first-mentioned transfer images, each of said segments of said third transfer image comprising a lighttransmitting and absorbing element; and providing the elements comprising at least another of said three transfer images with a material for absorbing light in a second wave length range different from said predetermined wave length range, the last-mentioned material being so associated with the last-mentioned elements as to control the wave length range of light transmitted by said last-mentioned elements.

13. The method of additive color photography which comprises exposing two photosensitive layers, each comprising a photosensitive heavy metal salt capable of having a developable image formed therein by exposure to actinic light, to produce in said photosensitive layers latent nonsegmented color-separation records; superposing said photosensitive layers with opposite sides of a support sheet with said records arranged in substantial registration; distributing a fluid processing composition between each of said photosensitive layers and one side of said support sheet; by said fluid, developing said latent color-separation records and producing in said photosensitive layers as a result of said development imagewise distributions of transferable image-forming substances; contacting first portions only of said support sheet with said photosensitive layers and squeezing out said fluid processing composition whereby there is no transfer of image-forming substances to said first portions of said support sheet; transferring image-forming substances by diffusion from said photosensitive layers to second portions only of said support sheet to form on said second portions segments of two positive transfer images corresponding to said color-separation records, said first and second portions of said support sheet being interspersed in a regular photographic screen pattern with said first portions on each side of said support sheet located in alignment with said second portions located on the opposite side of said support sheet; providing said second portions comprising one of said transfer images with a material for transmitting light in a predetermined portion of the visible wave length range; and providing said second portions comprising the other of said transfer images with a material for absorbing light in said predetermined portion of the visible wave length range, the last-mentioned material being so associated with the segments of said other transfer image as to determine the wave length range of the light transmitted by said second portions comprising said other transfer image.

14. The method of claim 13 wherein said second portions of said support sheet comprise recesses in the surfaces of said support sheet and said fluid processing composition is distributed between and in contact with said support sheet and said photosensitive layers substantially only in said recesses.

15. The method of claim 14 wherein said last-mentioned material is provided in said fluid composition distributed in said recesses in one side of said support sheet.

16. The method of claim 14 wherein the depth of said recesses is at least equal to one-half the thickness of said support sheet and said image segments of said one transfer image are formed in coplanar nonoverlapping relation in portions of a first discontinuous receiving layer and said segments comprising said second transfer image are formed in portions of a second discontinuous receiving layer located in substantially coplanar nonoverlapping relation with said portions of said first receiving layer.

17. The method of claim 14 wherein a first fluid composition is distributed between and in contact with one of said photosensitive layers and said support sheet for producing said segments comprising said one transfer image; a second fluid composition is distributed between and in contact with the other of said photosensitive layers and said support sheet for producing said segments comprising said other transfer image; and said fluid compositions contain said materials for determining the wave length range of the light transmitted by said second portions of said support sheet comprising said transfer images.

18. The method of claim 13 wherein said last-mentioned material is provided in the form of filter elements mounted on said second portions of said support sheet in alignment with said image segments comprising said other transfer image.

19. The method of additive color photography which comprises exposing two photosensitive layers, each comprising a photosensitive heavy metal salt capable of having a developable image formed therein by exposure to actinic light, to produce in said photosensitive layers latent nonsegmented color-separation records; superposing said photosensitive layers in registration with one another with opposite sides of a support sheet having in at least one of its surfaces a multiplicity of minute, spaced-apart recesses arranged in a photographic screen pattern, at least one of said photosensitive layers being superposed with one surface of said support sheet in contact with portions thereof between said recesses; thereafter distributing a fluid processing composition between each of said photosensitive layers and one side of said support sheet, said fluid distributed between said one side of said support sheet and said one photosensitive layer being squeezed from between said portions of said one surface and said one photosensitive layer whereby said fluid is retained substantially only in said recesses in contact with portions of said one photosensitive layer aligned with said recesses; by said fluid, developing said latent color-separation records and producing in said photosensitive layers as a result of the said development imagewise distributions of transferable image-forming substances; transferring said image-forming substances by diffusion from minute, spaced-apart areas of said one photosensitive layer to said support sheet and thereby forming on said support sheet in said recesses a first segmented, positive, transfer image corresponding to said color-separation record in said one photosensitive layer; transferring said image-forming substances by diffusion from minute, spaced-apart areas of the other of said photosensitive layers arranged in a screen pattern to the other side of said support sheet and thereby forming on said other side of said support sheet a second segmented, positive transfer image corresponding to said color-separation record in said other photosensitive layer, the segments comprising said second transfer image being spaced apart from one another and being located in alignment with the spaces between the recesses in which said segments of said first transfer image are formed, each of said image segments comprising a light-transmitting and absorbing element; providing the elements comprising said first transfer image with a material for transmitting light in a predetermined portion of the visible wave length range, said material being distributed in said recesses; and providing the elements comprising said second transfer image with a material for absorbing light in said predetermined portions of the visible wave length range, the last-mentioned material being so associated with said segments of said second transfer image as to determine the wave length range of the light transmitted by the last-mentioned elements.

20. The method of additive color photography which comprises exposing two photosensitive layers, each comprising a photosensitive heavy metal salt capable of having a developable image formed therein by exposure to actinic light, to produce in said photosensitive layers latent nonsegmented color-separation records; superposing said photosensitive layers with said records in registration on opposite sides of a support sheet having in its surfaces a multiplicity of minute recesses arranged in a photographic screen pattern with the recesses in each surface located opposite the spaces between the recesses in the opposite surface; distributing a fluid processing composition between each of said layers and said support in said recesses in contact with substantially only minute, spaced-apart areas of said photosensitive layers aligned with said recesses; by said fluid, developing said latent color-separation records and producing in said photosensitive layers as a result of said development imagewise distributions of transferable image-forming substances; transferring asid image-forming substancesby diffusion from substantially only said minute, spacedapart areas of said photosensitive layers tosaid support and thereby forming in said recesses segments of positive transfer images corresponding to said color-separation records, each of said segments comprising a light-transmitting and absorbing element located in one of said recesses; providing the elements comprising one of said transfer images with material for transmitting light in a predetermined portion of the visible wave length range; and providing the elements comprising the other of said transfer images with a material for absorbing light in said predetermined portion of said visible wave length range, said materials being provided in said recesses and being so associated with said segments of said transfer images as to determine the wave length range of the light transmitted by said elements.

21. The method of claim wherein the last-mentioned material is initially provided in said fluid composition which is distributed in said recesses in one side of said support sheet in contact with one of said photosensitive layers.

22. The method of claim 20 wherein a first fluid composition is distributed in said recesses in one side of said support in contact with one of said photosensitive layers for producing said elements comprising said one transfer image; and a second fluid composition is distributed in said recesses in said other side of said support in contact with the other of said photosensitive layers for producing said elements comprising said other transfer image, said first fluid composition containing the first-mentioned material and said second fluid composition containing the the last-mentioned material.

23. The method of claim 20 wherein each of said recesses has a depth which is at least equal to one-half the thickness of said support sheet, said segments comprising one of said transfer images are formed in coplanar, nonoverlapping relation in portions of a first discontinuous receiving layer and said segments comprising the other of said transfer images are formed in portions of a second discontinuous receiving layer located in substantially coplanar, nonoverlapping relation with said portions of said first discontinuous receiving layer.

24. The method of claim 20 wherein said segments of said transfer images are formed ni said fluid in said recesses, and, following formation of said transfer images, said photosensitive layers are separated from said sup port and said fluid is retained in said recesses.

25. The method of claim 24 wherein said materials for determining the wave length range of light transmitted by said elements are initially provided in said fluid retained in said recesses.

26. The method of claim 24 wherein said fluid retained in said recesses following separation of said photosensitive layers from said support is treated with a fluid reagent for preserving said image segments.

27. The method of claim 24 wherein the depths of said recesses exceed one-half the thickness of said support sheet and said fluid retained in said recesses forms layers in said recesses disposed in substantially co-planar, nonoverlapping relation and containing said segments of said transfer images.

28. A photographic film assemblage comprising, in combination, a pair of photosensitive layers each including a heavy metal salt capable of having a developable latent image formed therein by exposure to actinic light, a lighttransmitting support sheet having in at least one surface a multiplicity of minute spaced-apart recesses arranged in a photographic screen pattern, said photosensitive layers being arranged for superposition in contact with opposite surfaces of said support sheet in covering relation to said recesses, a fluid processing composition capable, when distributed between each of said photosensitive layers and said support sheet following exposure of said photosensitive layers, of reacting with said photosensitive layers for producing on said support sheet positive transfer images corresponding to latent images in said photosensitive layers, means releasably containing said fluid composition for distribution between each of said photosensitive layers and one side of said support sheet, and at least a colored filter material, capable of absorbing light within a predetermined portion of the visible wave length range to which at least one of said photosensitive layers is sensitive, carried by said support sheet for association with the segments of one of a pair of segmented transfer images, formed on said support sheet from one of said photosensitive layers during the processing thereof by said fluid, to determine the wave length range of light transmissible by said segments.

29. The photographic film assemblage of claim 28 wherein said colored filter material is provided initially in said fluid composition for distribution in said recesses between one of said photosensitive layers and said support sheet.

30. A photographic film assemblage comprising, in combination, a pair of photosensitive layers each including a heavy metal salt capable of having a developable latent image formed therein by exposure to actinic light, a light-transmitting support sheet, the opposite surfaces of said support sheet each having a multiplicity of minute spaced-apart recesses arranged in a photographic screen pattern, the recesses in each surface being located between the recesses in the opposite surface and the dimensions of the spaces between said recesses in each surface being at least equal to the corresponding dimensions of the recesses in the opposite surface, said photosensitive layers being arranged for superposition with opposite surfaces of said support sheet in covering relation to said recesses and in contact with portions of said surfaces located between said recesses, a fluid processing composition capable, when distributed between each of said photosensitive layers and said support sheet in said recesses therebetween in contact with minute spaced-apart portions of said each photosensitive layer, of reacting with said each photosensitive layer for producing in said recesses segments of a positive transfer image corresponding to the latent image in said portions of said photosensitive layer, means releasably containing said fluid composition for distribution in said recesses between each of said photosensitive layers and one side of said support sheet, and at least a colored filter material, capable of absorbing light within a predetermined portion of the visible wave length range to which at least one of said photosensitive layers is sensitive, carried by said support sheet for distribution in said recesses in at least one of said surfaces of said support sheet.

31. The photographic film assemblage of claim 30 wherein said colored filter material comprises said fluid composition provided for distribution in said recesses in said one surface of said support sheet.

32. The photographic film assemblage of claim 30 wherein each of said photosensitive layers is sensitive to light within a predetermined visible wave length range which is different from the wave length range of the light to which the other of said photosensitive layers is sensitive.

33. The photographic film assemblage of claim 30 wherein said recesses comprise a multiplicity of spaced parallel grooves in each surface of said support, the grooves in each surface being located between grooves in the opposite surface and the spacing between grooves in each surface being at least equal to the width of the grooves in the opposite surface.

34. The photographic film assemblage of claim 33 wherein the width of said grooves in each surface is substantially equal to the width of the spaces between grooves in the opposite surface and the depth of the grooves in each surface is less than half the thickness of said support sheet.

35. The photographic film assemblage of claim 33 wherein the width of the grooves in one surface of said support sheet is greater than the width of the grooves in 37. The photographic film assemblage of claim 3O wherein said support sheet is disposed between said photosensitive layers and means are provided for so securing together portions of said photosensitive layers as to prevent relative movement of said layers in planes parallel to the surfaces of said support sheet.

38. The photographic film assemblage of claim 30 wherein said filter material is provided in all of said recesses in at least one surface of said support sheet.

39. The photographic film assemblage of claim 30 wherein said fluid processing composition is provided in two containers disposed adjacent opposite surfaces of said support sheet for distribution in recesses in opposite surfaces of said support sheet, and said filter material is pro vided in said fluid composition in one of said containers.

40. The photographic film assemblage of claim 39 wherein a filter material capable of absorbing light within a substantially different visible wave length range from the first-mentioned filter material is included in the fluid composition in the other of said containers.

41. The photographic film assemblage of claim 30 wherein said fluid processing composition is carried in a pair of elongated rupturable containers, each container being located between a photosensitive layer and one sur face of said support, each of said containers being located in position to discharge its contents for distribution in the recesses in one of said surfaces of said support.

42. The photographic film assemblage of claim 30 wherein the sides of said recesses are substantially perpendicular to the surfaces of said support and the bottom surfaces of said recesses are substantially parallel to the surfaces of said support, and said filter material is provided as layers on the bottom surfaces of said recesses, all the recesses in each of said surfaces containing a filter material having substantially the same light-absorptive characteristics.

43. The photographic film assemblage as defined in claim 30 wherein said support sheet is secured between said photosensitive layers for movement with respect to said photosensitive layers, and said photosensitive layers are secured to one another against relative movement in planes generally parallel with said support sheet and for movement relative to one another toward and away from one another.

References Cited in the file of this patent UNITED STATES PATENTS 1,139,633 Bradshaw et al May 18, 1915 2,018,195 Thornton Oct. 22, 1935 2,614,926 Land Oct. 21, 1952 2,647,049 Land July 28, 1953 2,968,554 Land Ian. 17, 1961 

1. THE METHOD OF ADDITIVE COLLOR PHOTOGRAPHY WHICH COMPRISES EXPOSING TWO PHOTOSENSITIVE LAYERS, EACH COMPRISING A PHOTOSENSITIVE HEAVY METAL SALT CAPABLE OF HAVING A DEVELOPABLE LATENT IMAGE FORMED THERIN BY EXPOSURE TO ACTINIC LIGHT, TO PRODUCE IN SAID PHOTOSENSITIVE LAYERS LATENT NONSEGMENTED COLOR-SEPARATION RECORDS; SUPERPOSING SAID PHOTOSENSITIVE LAYERS WITH OPPOSITE SIDES OF A SUPPORT SHEET WITH SAID RECORDS INSUBSTANTIAL REGISTRATION; DISTRIBUTING A FLUID PROCESSING COMPOSITION BETWEEN EACH OF SAID PHOTOSENSITIVE LAYERS AND ONE SIDE OF SAID SUPPORT SHEET; BY SAID FLUID, DEVELOPING SAID LATENT COLOR-SEPARATION RECORDS AND PRODUCING IN SAID PHOTOSENSITIVE LAYERS AS A RESULT OF SAID DEVELOPMENT IMAGEWISE DISTRIBUTIONS OF TRANSFERABLE IMAGE-FORMING SUBSTANCES; TRANSFERRING SAID IMAGE-FORMING SUBSTANCES BY DIFFUSION SUBSTANTIALLY ONLY FROM MINUTE SPACED-APART AREAS OF SAID PHOTOSENSITIVE LAYERS ARRANGED IN A PHOTOGRTAPHIC SCREEN PATTERN TO SAID SUPPORT SHEET AND THEREBY FORMING ON SAID SUPPORT SHEET TWO SEGMENTED POSITIVE TRANSFER IMAGES CORRESPONDING TO SAID COLOR-SEPARATION RECORDS AND ARRANGED WITH THE SEGMENTS COMPRISING EACH OF SAID POSITIVE TRANSFER IMAGES SPACED APART FROM ONE ANOTHER AND LOCATED IN ALIGNMENT WITH THE SPACES BETWEEN THE SEGMENTS COMPRISING THE OTHER OF SAID TRANSFER IMAGES, EACH OF SAID IMAGE SEGMENTS COMPRISING A LIGHT-TRANSMITTING AND ABSORBING ELEMENT; PROVIDNG THE ELEMENTS COMPRISING ONE OF SAID TRANSFER IMAGES EITH A MATERIAL FOR TRANSMITTING LIGHNT IN A PREDETERMINED PORTION OF THE VISIBLE WAVE LENGTH RANGE; AND PROVIDING THE ELEMENTS COMPRISING THE OTHER OF SAID TRANSFER IMAGES WITH A MATERIAL FOR ABSORBING LIGHT IN SAID PREDETERMINED PORTION OF THE VISIBLE WAVE LENGTH RANGE, THE LAST-MENTIONED MATERIAL BEING SO ASSOCIATED WITH THE SEGMENTS OF SAID OTHER TRANSFER IMAGE AS TO DETERMINE THE WAVE LENGTH RANGE OF THE LIGHT TRANSMITTED BY THE LASTMENTIONED ELEMENTS. 